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SVC 820-Tankless Gas Troubleshooting Manual
Page | 9
Error Code
Code
Fault
Flow Rate/Maintenance:
Nothing Happens When
No
Water Is Flowing Through
Code
Unit. (Control Board
Displays Water Temp)
P1 Maintenance Warning:
Remedy
1.
2.
3.
4.
5.
Increase water flow rate or set higher temperature
New Installations: Ensure hot and cold water lines are not crossed
Check for plumbing crossover in the home
Clean water inlet filter
Check water flow sensor (may be jammed)
1.
2.
3.
Check hot water tap flow (clean aerator if necessary)
Clean water inlet filter
Increase flow rate or set higher temperature
1.
2.
Flush Heat Exchanger
High Altitude Installations: ensure proper altitude settings have been made
1.
2.
Check communications cable connection
Check # 4 dip switch setting is in the ‘ON’ position (Dip Set # 1 (Top), Dip
switch # 4 on the water heaters only)
1.
2.
Remove any vent blockage
Make sure venting meets all installation requirements
Water Flow Too Low
(Unit Will Still Be
Operable; Minimum Flow If maintenance requirements are met:
0.4 GPM To Activate @
o
1. Check water flow sensor
35 ) T)
Maintenance:
1L Water Heater Has
Buildup Of Lime/Scale
Deposits
03 MIC 185, MIC 6, & EZ Link
Maintenance Warning:
Air Intake Or Vent
Exhaust May Be Blocked
(Unit Will Still Be
Operable)
05
Installation Warning:
The vent Pipes On The
Vent Termination May
Not Be Connected (Unit
Will Still Be Operable)
If maintenance requirements are met:
1.
Check fan motor
Make sure all venting is properly sealed and meets all venting requirements (diameter;
vent lengths; venting material; venting obstructions; and all other installation
requirements as described in installation manual)
If installation requirements are met:
1.
Check Blower Motor
9
10 | Page
Maintenance:
10 Decrease Of Ventilation
Amount (Blower Motor)
Installation/Gas supply:
11 Ignition Failure
SVC 820 Tankless Gas Troubleshooting Manual
Clean any blockage in venting, Blower Motor, air intake
If maintenance requirements are met:
1.
Check Blower Motor
1.
2.
3.
4.
5.
Ensure you have gas to the appliance and valves are turned ‘ON’
Ensure gas type, gas pressure, and gas volume are correct
Bleed all air from gas lines
Ensure gas line, meter, and regulator are sized properly
Ensure appliance is properly grounded
If installation/gas supply requirements are met:
1.
2.
3.
4.
5.
Gas supply/Installation/
Maintenance:
12
1.
2.
3.
4.
5.
6.
7.
8.
Check Gas Control valve for open or short circuits
Ensure Igniter Rod is operational
Check igniter/Flame Rod(s) and Igniter/Flame Rod(s) wiring harness for
damage
Check Control Board
Check Flame Rod Status
Ensure gas type and pressure is correct
Bleed all air from gas lines
Ensure Flame Rod wire(s) is connected
Check Flame Rod(s) for carbon build-up
Ensure gas line, meter, and regulator are sized properly
Ensure appliance is properly grounded
Check power supply for proper voltage and voltage drops
Disconnect and re-connect all wiring harnesses on Gas Control Valve and
Control Board
Flame Failure (Had Main
If gas supply/installation/maintenance requirements are met:
Burner, Then Lost It)
1.
2.
3.
4.
10
Check gas valves for open or short circuits
Check flame rod(s) and flame rod(s) wiring harness for damage
Check PCB
Check flame rod(s) status
SVC 820-Tankless Gas Troubleshooting Manual
Indoor ONLY
Venting:
13
Flame Rod FL-2: Reads
Poor Or Improper
Combustion
Condensing only:
Maintenance:
Page | 11
Ensure intake and exhaust venting meet all installation requirements (diameter; vent
lengths; venting material; venting obstructions; and all other requirements as
described in the Use & Care manual {Make sure exhaust is not recirculating into fresh
air intake})
If venting requirements are met:
1.
2.
3.
4.
Remove any blockage from venting or from in front of vent termination
Verify altitude settings
Check Flame Rod FL-2
Check Blower Motor
Condensing Only:
1.
2.
Clean blockage in heat exchanger
Remove any blockage from Blower Motor and exhaust vent
Flue Temperature Too
High
14
Mid Efficiency & Condensing:
Mid Efficiency &
Condensing:
Over Heat Limiter (OHL)
Fault
Maintenance:
Boiling Safety Device
15 (Heat Exchanger
temperature reached
207 F degrees for more
than 15 seconds)
Maintenance:
Outlet Water
16 Temperature Is Above
Remote Thermostat
Setting
If ‘Condensing’ maintenance requirements are met:
1.
2.
3.
4.
5.
Verify “U” connector is connected to Control Board
Verify wiring harness is connected to OHL
Check heat exchanger for cracks and/or separations
Inspect Overheat Wrap (Overheat wrap failure: Replace unit)
Check thermal overload sensor (condensing models only)
1.
2.
Flush Heat Exchanger (lime/scale buildup)
Check for closed water heater inlet valve or restrictions in cold water inlet
pipe (must be fully open)
0
On commercial water heater, lower set point temperature below 180 F at
high altitudes
3.
If maintenance requirements are met:
1.
Check Heat Exchanger Thermistor
1.
2.
Check for clogged Heat Exchanger
Check for restrictions in airflow around unit and vent terminal
If maintenance requirements are met:
1.
2.
3.
Check Outlet Thermistor
Check Heat Exchanger Thermistor
Check gas valve
11
12 | Page
Malfunction Of
24
Operational Switch
SVC 820 Tankless Gas Troubleshooting Manual
1.
2.
3.
Turn off water. Disconnect Remote Control and retry
Verify unit is electrically grounded
Press MIN and MAX button on Control Board to reset
Condensing Only:
Condensing Only:
Maintenance:
Neutralizer Is clogged
1.
2.
3.
4.
5.
Ensure shipping cap for drain line is removed and drain line is not blocked
Clear all neutralizer drainage ports inside of unit
Clear neutralizer drainage line outside of unit
Clean air inlet screen
Clean heat exchanger fins
If maintenance requirements are met:
1.
29
Mid Efficiency &
Condensing:
Check neutralizer water level electrode
Mid Efficiency & Condensing:
1.
2.
Clean air inlet screen
Clean heat exchanger fins
31 Inlet Thermistor
1.
2.
3.
Check Thermistor wiring for damage
Check and clean scale from Thermistor
Ohm Thermistor
Heat Exchanger
32
Thermistor
1.
2.
3.
Check Thermistor wiring for damage
Check and clean scale from Thermistor
Ohm Thermistor
1.
2.
3.
Check Thermistor wiring for damage
Check and clean scale from Thermistor
Ohm Thermistor
Maintenance:
Heat Exchanger
Temperature Is Too Low
33 Outlet Thermistor
12
SVC 820-Tankless Gas Troubleshooting Manual
1.
2.
3.
34 Ambient Thermistor
Page | 13
Check Thermistor wiring for damage
Check and clean Ambient Thermistor
Ohm Thermistor
If wiring and component readings are normal:
1.
2.
Check for restrictions in airflow around unit and vent terminal
Ensure fan blade is tight on motor shaft and spins freely
1.
2.
Check that all Thermistors are secured to proper connections on Control
Board
Check that all quick connectors between Control Board and Thermistors
1.
2.
Check Gas Control Valve wiring harness for loose or damaged terminals
Ohm Gas Control Valve
1.
2.
Check PGFR Valve wiring harness for loose or damaged connections
Ohm PGFR Valve
1.
2.
3.
Ensure Blower Motor will turn freely. Motor will operate with a small amount
of restriction
Check wiring harness to Motor for damaged and/or loose connections
Check venting length not to exceed max lengths and bends
65 Water Control Valve
1.
2.
Check Water Control Valve wiring harness for loose or damaged terminals
Check for proper voltage to Water Control Valve
66 Water Bypass Valve
1.
2.
Check Water Bypass Valve wiring harness for loose or damaged terminals
Check for proper voltage to water by-pass solenoid
71 Gas Control Valve
1.
2.
Check Gas Control Valve wiring harness for loose or damaged terminals
Ohm Gas Control Valve
1.
2.
Ensure Flame Rod(s) is touching flame when unit fires
Check inside burner chamber for any foreign material blocking flame at Flame
Rod(s)
Check all wiring to Flame Rod for damage
Check Flame Rod for proper voltage
Remove Flame Rod and check, clean with steel wool (Do not use sandpaper)
35 Improper Thermistor
Connection
51 Gas Control Valve
52
PGFR Valve
(Modulating Valve)
Installation/Maintenance:
61
Blower Motor
72
Flame Rod
(Detected False Flame)
3.
4.
5.
13
14 | Page
SVC 820 Tankless Gas Troubleshooting Manual
1.
2.
76
Communication Fault
With Remote Control
79
Blower Motor
Current Fault
3.
1.
Check Remote Control wiring for loose or damaged connections
Bypass Remote Control: connect Remote Control directly to remote
connection at bottom of the heater. Replace cable if found to be faulty
Remove water heater power cord from 3 prong outlet. Disconnect the
Remote Control. Plug heater back into supply and test heater without Remote
Control connected
2.
Ensure Blower Motor will turn freely. Motor will operate with a small amount
of restriction
Check Fan Motor for proper voltage and for water (condensation) damage
1.
2.
Ohm Gas Control Valve
Check voltage of all Flame Rods
80
&
Gas Control Valve
81
Installation:
82 Control Board Is Not
Programmed.
Verify Program Chip is installed
Maintenance/Installation:
Clean any blockage in Heat Exchanger, Blower Motor, inlet flue and exhaust flue
90
Blocked Flue/Air Intake
Condensing Only:
Maintenance Warning:
92
Neutralizer Needs To Be
Replaced (Unit Will Still
Be Operable)
Replace Neutralizer
Condensing Only:
Maintenance:
93
Neutralizer Must Be
Replaced (Unit Will NOT
Operate)
Maintenance/Installation:
99 Blower Motor Cannot
Vent
14
Replace Neutralizer
1.
2.
Clear vent blockages
Check for blocked Heat Exchanger